Lever jack



April 14, 1925. 1,533,737

P. JACOMY LEVER JACK FildMay 28, 192;

1 52 FJ'J y I 9 Fl v Patented Apr. 14, 1925.

UNITED STATES 1,533,737 PATENT OFFICE.

PIERRE JACOMY, or roUtoUsnrnANoE, Assienoa TO socin'rn ANONYME LA GHEVRETT'E, or roULoUsE, I-IAUTE-GARON'NE, FRANCE.

LEVER I JACK.

Application filed May 28, 1923. Serial No. 642,070.

To all 107mm it may concern:

Be it known that I, Pinnnn Jncoarr, a citizen of the French Republic, residing 40 Rue des Amidonniers, Toulouse, Haute 5 Garonne, France, have invented new and useful Improvements in a Lever Jack, of which the following is the specification.

This invention relates to a system of lever jack, characterised-by the use of a lever t 10 the first order the point of application of the load of which is compelled to follow a recti-' linear trajectory situated at an invariable distance from the fulcrum, owing to the use of a lever arm of determined profile, sliding relatively to the fulcrum.

A lever jack thus characterised allows to instantaneously lift the load and, the distance from the fulcrum to the point of application being constant, the stress to be developed at the end of the large lever arm does not practically vary during the ascent of the load. 1

The accompanying drawing illustrates by way of example a form of construction of a jack in accordance with the invention, more particularly devised for the lifting of motor vehicles.

Fig. 1 is a vertical section of the whole of the apparatus according to line A -A of Fig. 3.

Fig. 2 is a side view with vertical section according to line BB of Fig. 3.

Fig. 3 is a plan view with horizontal section according to line C0 of Fig. 1.

and having a vertical guide for slidably receiving a lifting rod 3 having on one side rack teeth 3 and jointed at its lower part to the end 1 of a lever 5 the outer curved profile of which bears on a roller 6 mounted on an axis 7 secured in the side cheeks of the frame 1. The upper end or head of the lifting rod 3 is provided with a shoe 8 on which can be turned down a block or lift piece 9 permitting to use the apparatus under axles situated at different heights. This lift-piece 9 is pivoted at 10 on the shoe 8 and the bearing faces 11 and 12 under the load are, as usual, striated for ensuring suitable adherence.

The curved lever 5 is brought back in the position which corresponds to the end of the lever stroke of thejlifting rod 3, by a coil spring 13 the ends of which are secured, on

The apparatus comprises a fran'ie '1, pro-, vided with a base 2 bearn'ig on the ground,

the one hand, on the frame at 1 1 and, on the other hand, on the lever 5 at 15; the mechanical features of this spring are determined of the frame 1 and subjected to the action of a counterweightQl, acts for releasing the l fting rod 3 at the time of its descent or for constantly holding it in all its positions of ascent. The counterweight 21 loose on the axis 22 acts upon one or the other of the two radial abutments of this axis for angularly urging it in a direction or the other.

lVith its essential elements thus described the apparatus operates in the following man ner:

The jack being placed under the vehicle with the lift-piece 9 or the shoe 8 arranged under one of the axles, the counterweight 21 is raised for causing the pawl 19 to come into engagement with the rack 3; it then suffices to exert a single pressure, at the end of theoperating tube 16 forensuring the as-- cent of the rod 3 and consequently the lifting oftho vehicle and the pawl 19 held in engagement with the rack 2-3 holds the said vehicle lifted at any desired height.

It is to be noted that, during the lifting operation, the curved lever 5 takes a bearing on the roller 6 and the axis 4 follows the rectilinear movement of the rod 8, without the movement of the load relatively to the fulcrum of the lever materially varying; in

practice, the useful stroke of the lifting rod 3 is equal to twice the small theoretical arm of the system of lever.

For bringing back the load upon the ground, it sutlices to send the counterweight 21 backward by using the tube 16, then to fit the said tube on the curved lever, to slight 1y lift the load for releasing the pawl 19 which automatically moves down outwardly and to act upon the tube 16 for braking the descent of the vehicle.

As soon as the wheels touch the ground,

ion

the apparatus is released and removed by nalled through the housing, a pawl keyed to holding it by the end of the lever owing the shaft within the housing and engageab-lc to the action of the spring. with the toothed lifting rod, a counterweight What I claim as my invention and desire keyed to the shaft exteriorly of the housing, 15 5 to secure by Letters Patent is: a curved lever pivoted to the lower end of A jack comprising a frame,- a base at the the rod and extending through and above lower end thereof the frame and base being the base, and a roller journalled in the base formed with a vertical guideway, a toothed for supporting the lever. lifting rod slidable in the guide, a housing In testimony whereof I have signed my 20 10 formed on the side of the frame and comname to this specification.

municating with the guideway, a shaft jour- PIERRE JACOMY. 

